Methods of treating wells

ABSTRACT

A method of and apparatus for treating wells to provide surface controlled subsurface safety systems in the wells, whether previously completed wells or newly completed wells. A method and apparatus is provided for installing receptacles in the well flow conductors below the surface for receiving surface controlled subsurface safety valves therein for controlling undesired flow from the well in the event of emergency, disaster or accident damaging the well surface flow controlling system or threatening the integrity thereof. Also, a method and apparatus is provided for installing a hanger for well flow conductors in the well casing below the surface for supporting the flow conductor or conductors in the well casing below the surface and then installing the receptacles in the well flow conductors below the surface for receiving surface controlled subsurface safety valves therein.

United States Patent Sizer et al.

[451 Mar. 18, 1975 1 1 METHODS OF TREATING WELLS [75] Inventors: Phillip S. Sizer, Dallas; Carter R.

Young, Lewisville, both of Tex.

[73] Assignee: Otis Engineering Corporation, Dallas, Tex.

[22] Filed: Mar. 23, 1973 [21] Appl. No.: 344,363

Related U.S. Application Data [62] Division of Ser, Nov 210,727, Dec. 22, 1971.

[52] U.S. Cl 166/298, 166/72, 166/315 [51] Int. Cl... E2lb 23/00, E2lb 29/00, E2lb 43/00 [58] Field of Search 166/277, 72, 297299, 166/313, 315, 71, 55.1, 55,125

[56] References Cited UNITED STATES PATENTS 3,216,501 11/1965 Page 166/72 3,380,528 4/1968' Timmons.... 166/277 3,434,543 3/1969 Webb 166/315 X 3,606,926 9/1971 Schwegman 166/315 3,696,868 10/1972 Taylor 166/315 Primary Examiner-David H; Brown [57] ABSTRACT A method of and apparatus for treating wells to provide surface controlled subsurface safety systems in the wells, whether previously completed wells or newly completed wells. A method and apparatus is provided for installing receptacles in the well flow conductors below the surface for receiving surface controlled subsurface safety valves therein for controlling undesired flow from the well in the event of emer gency, disaster or accident damaging the well surface flow controlling system or threatening the integrity thereof. Also, a method and apparatus is provided for installing a hanger for well flow conductors in the well casing below the surface for supporting the flow condoctor or conductors in the well casing below the surface and then installing the receptacles in the well flow conductors below the surface for receiving surface controlled subsurface safety valves therein.

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SHEET 110F18 PATENTEU I 81975 3,871,456- SHEET 12.]? 1s METHODS OF TREATING WELLS This application is a division of our co-pending'application Ser. No. 210,727, filed Dec. 22, 1971.

SUBJECT MATTER AND OBJECTS OF THE INVENTION This invention relates to new and useful improvements in methods of and apparatus for equipping wells with surface controlled subsurface safety valves, either before or after the well has been completed in the usual manner.

l-leretofore, when a well has been completed it has been necessary to remove the tubing string or strings from within the well bore in the casing, first killing the well, unseating the packers, and then removing the string and packers and other fittings from the well prior to installing new strings of pipe, refitted or new packers, subsurface safety valve receptacles and control fluid lines for the valves, then reinstalling the tubing hanger and surface controls and flow lines, including an exit fitting for the control fluid pressure line at the surface before the well could be returned to production. This is an expensive and time consuming operation, and may result in damage to the producing formation of the well as a result of the loading fluid used and other operations performed in making the revised installation. Such operations are expensive due to the heavy equipment and the long period of time required for their performance. Also, the deleterious effects of the treating and loading fluids on the producing formation often result in a reduction in the productivity or flow of desirable fluids from the formation and a commensurate reduction in the value of the well.

It is, therefore, one object of the invention to provide a new and improved method of and system for installing surface controlled subsurface safety valves in the conductor or conductors of wells.

A particular object of the invention is to provide a method of and system for installing surface controlled subsurface safety valves in the flow conductor or conductors of wells which have been previously completed with the flow conductor or conductors in place therein.

An important object of the invention is to provide a method of and apparatus for disconnecting the upper portion of one or more flow conductors in a well from the remainder of such conductors therebelow and installing a receptacle and replacement upper flow conductor portion in flow communication with each of such flow conductors therebelow with a surface controlled subsurface safety valve in such replacement upper flow conductor portion for controlling fluid flow through each such flow conductor.

A further object of the invention is to provide a method and apparatus of the character set forth wherein the receptacle and replacement upper flow conductor portion are provided with means for detachably connecting the receptacle and replacement upper flow conductor portion for each flow conductor of the well to permit removal and replacement of the replacement upper flow conductor portion and the safety valve when desired.

Still another object is to provide a method and apparatus as set forth wherein the surface controlled subsurface safety valve is insertable and removable independently of the replacement upper flow conductor portion.

A further important object of the invention is to provide a method and apparatus of the character set forth wherein a supplementary surface controlled subsurface safety valve may be installed in the replacement upper flow conductor portion in the event of the original safety valve becoming inoperative or ineffective.

A further object of the invention is to provide in a method and apparatus of the character set forth means for directing a hanger into place over a flow conductor in place in the well and activating the hanger into anchoring supporting engagement with the casing and the flow conductor either before or after the upper portion of the flow conductor above the hanger has been removed from connection with the flow conductor therebelow.

A further particular object of the invention is to provide a method and apparatus for servicing wells to provide a subsurface hanger in the well engaging between the flow conductor and the well casing and supporting the flow conductor therebelow against longitudinal downward movement in the casing, then installing a receptacle and replacement upper flow conductor portion above the hanger in flow communication with the upper end of the flow conductor remaining in place in the well casing for receiving a surface controlled subsurface safety valve in the receptacle for controlling fluid flow through the conductor and replacement upper flow conductor portion to the surface in the event of either an imminent or impending disaster or under any other desired circumstances, and wherein the method and apparatus is installable in wells already previously completed without removing from the well flow conductors, or packer, or other well tools connected therewith already in place in the well below the point of connection of the hanger with the flow conductor.

A further object of the invention is to provide a method and apparatus of the character described which may be used with either single flow conductor well installations or in multiple flow conductor well installations for controlling fluid flow through the conductors to the surface.

Still another object of the invention is to provide a method and apparatus of the character described which is adapted for use in wells in which the well is serviced or treated by means of through the flow line pump-down operations, and in which the pump-down tools may be moved through the surface controlled subsurface safety valve and receptacle and hanger without affecting the customary operation of such pump-down tools.

It is still another object of the invention to provide a method and apparatus of the character described wherein the installation may be made without rotary manipulation of the flow conductor in place in the well, particularly that portion thereof left in place in the well; and wherein the surface controlled subsurface safety valve and replacement upper flow conductor portion may be removed and replaced without rotation thereof.

Still another object of the invention is to provide an apparatus and method of the character described wherein the replacement upper flow conductor portion or extension and the well equipment at the surface may be readily replaced with a minimum of cost, time, and labor by merely replacing the well head, if damaged, the replacement upper flow conductor portion and the 

1. A method of treating a well having a producing flow conductor in place therein to provide a surface controlled subsurface safety valve in said flow conductor for controlling flow through said conductor which includes: plugging the producing flow conductor at a predetermined point below the surface to close off flow from the well therethrough; selecting a desired location in the flow conductor below the surface for parting the flow conductor; parting the flow conductor at such location; removing the parted upper portion of the conductor from the well; inserting a replacement upper flow conductor portion having a surface controlled normally closed subsurface safety valve therein in the well in flow communication with the portion of the original flow conductor left in place in the well below the point of parting for controlling flow through said original flow conductor and through said replacement portion; unplugging the flow conductor below the safety valve; and controlling operation of said surface controlled subsurface safety valve from the surface in response to predetermined undesired conditions in the well or at the surface to close off flow through the flow conductor.
 2. The method of claim 1 including the additional step of removing and reinserting said subsurface safety valve by means of said replacement upper flow conductor portion for servicing said safety valve.
 3. The method of claim 1 including the additional step of removing and replacing said subsurface safety valve through said replacement upper flow conductor portion without removing said replacement upper flow conductor portion.
 4. The method of claim 2 including the step of supporting the lower original portion of the flow conductor left in place in the well while said replacement upper flow conductor portion is removed from the well.
 5. A method of treating a well having a production flow conductor in place therein to provide a surface controlled subsurface safety valve for controlling flow through said production flow conductor which includes: closing said production flow conductor below the surface to close against flow of well fluids from the well therethrough; parting said production flow conductor at a selected level below the surface and above said point of closing off flow therethrough; removing the parted upper portion of the production flow conductor from the well; installing in the well a replacement upper flow conductor portion having a surface controlled safety valve therein in flow communication with the production flow conductor portion left in place in the well for controlling flow of well fluids from the well through said production and replacement upper flow conductor portions; opening said production flow conductor below the safety valve; then controlling flow of well fluids through the production flow conductor by controlling operation of the safety valve.
 6. The method of claim 5 wherein the safety valve is controlled from the surface in response to predetermined conditions sensed in or at selected portions of the well installation.
 7. The method of claim 5 with the additional steps of disconnecting said replacement upper flow conductor with the safety valve therein from the portion of said production flow conductor left in the well for removal of said safety valve from the well for servicing the same.
 8. The method of claim 5 including the additional step of removing and replacing said subsurface safety valve through said replacement upper flow conductor portion without removing said replacement upper flow conductor portion.
 9. The method of claim 5 including the steps of parting the flow conductor at a selected threaded joint therein by loosening said threaded joint for unscrewing by detonating an explosive adjacent said selected threaded joint while applying a torque in one direction below said threaded joint and a torque in the opposite direction above said threaded joint to loosen said selected threaded joint; then rotating the flow conductor above said loosened threaded joint to disconnect said flow conductor above said selected threaded joint from the flow conductor therebelow to part said flow conductor at said selected threaded joint before removing the parted portion above the selected threaded joint from the well.
 10. The method of claim 5 including the step of supporting said production flow conductor on the well casing at a selected point below the surface and then parting said production flow conductor at a point above said selected point of support to free the upper portion of said production flow conductor above the point of parting for removal from the well, leaving the portion left in place in the well therebelow supported on the casing.
 11. The method of claim 10 wherein the portion of the production flow conductor left in place in the well is supported adjacent its upper end on the uppper portion of the well casing below the surface of the well.
 12. The method of claim 5 wherein the production flow conductor is parted by unscrewing said flow conductor at a selected threaded joint.
 13. The method of claim 12 wherein said selected threaded joint is loosened for unscrewing by detonating an explosive at a level adjacent said selected threaded joint to jar and loosen the thread of said selected threaded joint; then rotating the production flow conductor above said joint to disconnect the same so that the upper portion of the production flow conductor is detached from the lower portion for removal from the well.
 14. The method of claim 5 including the additional step of removing and reinserting said subsurface safety valve by means of said replacement upper flow conductor portion for servicing said safety valve.
 15. The method of claim 14 including the step of supporting the lower original portion of the flow conductor left in place in the well while said replacement upper flow conductor portion is removed from the well.
 16. The method of claim 5 wherein the productIon flow conductor is parted by severing the same by cutting the conductor.
 17. The method of claim 16 wherein the production flow conductor is cut by mechanical cutting means.
 18. The method of claim 16 wherein the production flow conductor is cut by a chemical type cutter.
 19. A method of treating a cased well having a production flow conductor in place therein to provide a surface controlled subsurface safety valve in the well below the surface thereof for controlling flow through said production flow conductor which includes: plugging said production flow conductor to close off flow from the well therethrough; supporting the flow conductor in the casing at a selected subsurface level; parting said production flow conductor above said selected subsurface level; removing the upper parted portion of the production flow conductor above the point of parting from the well; inserting a replacement upper flow conductor portion having a surface controlled safety valve therein in the well and connecting the same in flow communication with the upper end of the portion of said production flow conductor left in the well; unplugging said production flow conductor; then controlling flow of well fluids through the conductor to the surface by operation of said safety valve.
 20. The method of claim 19 including the further steps of providing a guide from the surface to the portion of the production flow conductor left in the well for guiding the replacement upper portion and the safety valve connected therein into position to be connected in flow communication with the portion of the flow conductor left in the well; and removing said guide after said replacement upper flow conductor has been connected in flow communication with said portion of said production flow conductor left in the well and prior to unplugging said production flow conductor.
 21. A method of treating a well having a plurality of production flow conductors therein to provide each such conductor with a surface controlled subsurface safety valve in the well below the surface thereof for controlling fluid flow through each respective production flow conductor which includes: closing off flow through each of said production flow conductors at a selected point below the surface; parting each of said production flow conductors at a selected level below the surface and above the point at which flow therethrough is closed off; removing the parted upper portion of each flow conductor from the well; installing in the well separate replacement upper flow conductor portions having surface controlled subsurface safety valves therein each connected in flow communication with one of the production flow conductors left in place in the well for controlling fluid flow through said flow conductors; opening each of said production flow conductors at said point of closure to permit flow of fluids from the well through said conductor; then controlling fluid flow from the well through each of said flow conductors by operation of the safety valve in the replacement upper flow conductor portion thereof.
 22. The method of claim 21 including the additional step of removing and reinserting said subsurface safety valve by means of replacement upper flow conductor portion for servicing said safety valve.
 23. The method of claim 21 including the additional step of removing and replacing said subsurface safety valve through said replacement upper flow conductor portion without removing said replacement upper flow conductor portion.
 24. The method of claim 22 including the step of supporting the lower original portion of the flow conductor left in place in the well while said replacement upper flow conductor portion is removed from the well.
 25. The method of claim 21 including the step of supporting each of said flow conductors on the well casing at a selected point below the surface and then parting each of said flow conductors at a point above said selected point of support to free the upper portion of said fLow conductor above the point of parting for removal from the well, leaving the portion left in place in the well therebelow supported on the casing.
 26. The method of claim 25 wherein the flow conductors left in place in the well are supported adjacent their upper ends on the upper portion of the well casing below the surface of the well.
 27. The method of claim 21 including the step of providing a guide from the surface to each separate flow conductor portion left in place in the well for directing the respective separate replacement upper flow conductor portions into flow communication with a predetermined selected one of said flow conductor portions left in place in the well.
 28. The method of claim 27 including the additional step of removing the guide for each of said flow conductor portions from the well after said replacement upper flow conductor portion has been connected in flow communication with the predetermined selected one of said flow conductors left in place in the well.
 29. The method of claim 28 wherein the guide is removed from each of said flow conductors prior to opening said flow conductor below the safety valve to flow of well fluids therethrough.
 30. The method of producing well fluids from a well having a plurality of vertically spaced subsurface earth producing zones penetrated by the well bore, and having a plurality of production tubing strings extending into the well bore and means isolating said zones from each other in the well bore with the tubing strings each communicating with a separate one of the respective earth zones, hanging said tubing strings from a hanger assembly in the well bore below the earth surface for supporting the upper ends of said tubing strings therebelow in said well bore, parting the tubing strings at a point below the surface of the well and above and in upwardly spaced relation to the tubing hanger assembly above the upper earth producing zone in the well bore, removing the upper portions of the tubing strings above the part from the well, connecting receptacle members to the upper end of each lower tubing string above the tubing hanger assembly, running into the well above the receptacle members a plurality of safety valves supported upon an upper plurality of tubing strings and landing said safety valve assemblies in said receptacle members in a position communicating each of said upper tubing strings with a separate lower tubing string and a separate producing zone in the well, operating said safety valve assemblies to control flow from said earth zones through said separate tubing strings, and supplying control fluid pressure from the surface to said safety valve assemblies to allow flow of fluid from the earth zones through the tubing strings and relieving the control fluid pressure from the safety valve assemblies to shut off flow from the earth zone through the tubing strings.
 31. The method of claim 30, including running a shifting tool into the well through one of said upper tubing strings and operating said safety valve means to establish flow through said tubing strings from one of said earth zones, running into said safety valve assembly through the upper tubing string of said last-mentioned tubing strings an auxiliary safety valve assembly to normally shut off flow through said last-mentioned tubing strings, and applying said control fluid pressure to said auxiliary safety valve assembly to establish flow through said last-mentioned tubing strings. 